EFFECT OF INTRAVENOUS AND INTRACAROTID INJECTIONS OF HYPERTONIC FLUIDS ON THE RELEASE OF MELANOCYTE-STIMULATING HORMONE FROM THE RAT POSTERIOR PITUITARY LOBE INCUBATED IN SITU

1975 ◽  
Vol 66 (1) ◽  
pp. 85-91 ◽  
Author(s):  
A. CYRKOWICZ ◽  
W. Z. TRACZYK

SUMMARY The posterior pituitary lobe of male rats under urethane anaesthesia was incubated in situ. The pituitary gland was exposed by the transpharyngeal approach. The posterior lobe remained in neural and partial vascular connexion with the hypothalamus, whereas the anterior lobe was entirely removed. Incubation fluid was collected and its melanophore-stimulating activity was assayed in hypophysectomized frogs. No effect was observed after the i.v. injection of 1 ml 120 μm-NaCl with 60 μm-CaCl2 or isotonic NaCl solution. Hypertonic solutions of 5% NaCl and 25% glucose injected intravenously to the limit of 0·5% of the body weight, transiently enhanced the release of MSH from the posterior pituitary lobe by 66% (significant) and 15% (not significant) respectively. Intracarotid injection of 0·3 ml 5% NaCl solution resulted in the highest increase (95%) of MSH release.

1934 ◽  
Vol 30 (6) ◽  
pp. 634-634
Author(s):  
P. Badul

The posterior lobe of the pituitary gland in a bull is free of prolan, while in a human it contains prolan. Only here it can be found in that part of the posterior pituitary lobe adjacent to the anterior lobe. In the bull, too, this part of the pituitary gland is completely free of prolan content. Histological examination shows that in humans, this part of the posterior lobe is crossed by bands of cells from the anterior lobe, which consist exclusively of basophilic cells.


Author(s):  
Aihuiping Xue ◽  
Ru Kong ◽  
Qing Yang ◽  
Mark C. Eldaief ◽  
Peter Angeli ◽  
...  

Distinct regions of the cerebellum connect to separate regions of the cerebral cortex forming a complex topography. While cerebellar organization has been examined in group-averaged data, study of individuals provides an opportunity to discover features that emerge at a higher spatial resolution. Here functional connectivity MRI was used to examine the cerebellum of two intensively-sampled individuals (each scanned 31 times). Connectivity to somatomotor cortex showed the expected crossed laterality and topography of the body maps. A surprising discovery was connectivity to the primary visual cortex along the vermis with evidence for representation of the central field. Within the hemispheres, each individual displayed a hierarchical progression from the inverted anterior lobe somatomotor map through to higher-order association zones. The hierarchy ended at Crus I/II and then progressed in reverse order through to the upright somatomotor map in the posterior lobe. Evidence for a third set of networks was found in the most posterior extent of the cerebellum. Detailed analysis of the higher-order association networks revealed robust representations of two distinct networks linked to the default network, multiple networks linked to cognitive control, as well as a separate representation of a language network. While idiosyncratic spatial details emerged between subjects, each network could be detected in both individuals, and seed regions placed within the cerebellum recapitulated the full extent of the spatially-specific cerebral networks. The observation of multiple networks in juxtaposed regions at the Crus I/II apex confirms the importance of this zone to higher-order cognitive function and reveals new organizational details.


Author(s):  
Aihuiping Xue ◽  
Ru Kong ◽  
Qing Yang ◽  
Mark C. Eldaief ◽  
Peter Angeli ◽  
...  

Distinct regions of the cerebellum connect to separate regions of the cerebral cortex forming a complex topography. While key properties of cerebellar organization have been revealed in group-averaged data, in-depth study of individuals provides an opportunity to discover functional-anatomical features that emerge at a higher spatial resolution. Here functional connectivity MRI was used to examine the cerebellum of two intensively-sampled individuals (each scanned across 31 MRI sessions). Connectivity to somatomotor cortex showed the expected crossed laterality and inversion of the body maps between the anterior and posterior lobes. A surprising discovery was connectivity to the primary visual cortex along the vermis with evidence for representation of the central field. Within the hemispheres, each individual displayed a hierarchical progression from the inverted anterior lobe somatomotor map through to higher-order association zones. The hierarchy ended near Crus I/II and then progressed in reverse order through to the upright somatomotor map in the posterior lobe. Evidence for a third set of networks was found in the most posterior extent of the cerebellum. Detailed analysis of the higher-order association networks around the Crus I/II apex revealed robust representations of two distinct networks linked to the default network, multiple networks linked to cognitive control, as well as a separate representation of a language network. While idiosyncratic spatial details emerged between subjects, each of these networks could be detected in both individuals, and small seed regions placed within the cerebellum recapitulated the full extent of the spatially-specific cerebral networks. The observation of multiple networks in juxtaposed regions at the Crus I/II apex confirms the importance of this zone to higher-order cognitive function and reveals new organizational details.


Author(s):  
O. I. Tiron

Despite the fact that the main pathogenetic factor in the development of burn disease is the alteration of the skin, the severity of the condition of patients in the acute period of the disease is due to systemic changes in the body caused by thermal factor. Being a powerful stress factor, severe burns are accompanied by activation of the hypothalamic-pituitary system. Although thyroid hormones are not considered typical "stress hormones", they also play a role in maintaining vasomotor function under stress. The question of thyroid dysfunction on the background of burn injury remains debatable, and scientific data on its morphological and ultramicroscopic changes are quite limited. The aim of the work is to establish microscopic and submicroscopic changes of the thyroid gland of experimental animals in the stage of shock after thermal trauma of the skin. Experimental studies were performed on 12 white adult male rats, which received a thermal burn of the skin of 2-3 degrees with a lesion area of 21-23 % of the skin. An infusion of 0.9 % NaCl solution at a dose of 10 ml/kg was performed into the inferior vena cava. Collection of material for histological and electron microscopic examinations was performed according to generally accepted methods. Histological specimens were examined using a MIKROmed SEO SCAN light microscope and photo-documented using a Vision CCD Camera with an image output system from histological specimens. Ultrathin sections made on an ultramicrotome UMPT-7 were contrasted with uranyl acetate, lead citrate according to the Reynolds method and studied under an electron microscope PEM-125K. Conducted micro- and submicroscopic studies of the structural components of the thyroid gland a day after the reproduction of thermal trauma to the skin on the background of the introduction of 0.9 % NaCl solution revealed reactive adjunctive-compensatory changes and initial manifestations of destruction. Vascular, stromal and parenchymal components of the organ in the stage of shock after burns correspond to the state of "stress" as a reaction to pathological exogenous exposure, and the intensification of metabolic processes in the affected organism of experimental animals.


1967 ◽  
Vol 39 (4) ◽  
pp. 485-NP ◽  
Author(s):  
S. TALEISNIK ◽  
J. DE OLMOS ◽  
R. ORÍAS ◽  
MARÍA E. TOMATIS

SUMMARY The effect on the content of melanocyte-stimulating hormone (MSH) activity in the pituitary of electrolytic lesions placed in different regions of the hypothalamus was studied in male rats. Lesions in the paraventricular nuclei resulted, after 15 days, in a decrease of pituitary MSH activity to 20·4 ± 4·5%/mg. gland as compared with the controls, without changes in the weight of the hypophyses. In a group of animals in which the lesions failed to destroy the paraventricular nuclei completely the MSH activity in the pituitary was 66·4 ± 7·5% of that of controls and the weight of the gland was significantly higher. Hypothalamic lesions in the median eminence of the tuber cinereum produced 24 hr. later a decrease of pituitary MSH activity to 6·6 ± 0·8%, but 15 days later the values/mg. gland were almost normal. Lesions placed in the mammillary bodies or in the nucleus caudatus did not affect pituitary MSH content. Extracts of stalk-median eminence or posterior lobe from animals with lesions in the paraventricular nuclei, failed to show MSH-releasing factor as it is found in intact animals, nor did they contain MSH-release-inhibiting factor. The results support the concept that the paraventricular nuclei are involved in the control of pituitary MSH secretion and suggest that the MSH content of the disconnected hypophysis is to some degree regulated autonomously.


1927 ◽  
Vol 23 (2) ◽  
pp. 239-243
Author(s):  
A. A. Sukhov

The pituitary gland or gl. pituitaria is an organ lying at the base of the brain in a cavity formed by the sella turcica at the front, back, and bottom, and by the sinus venosus cavernosus dex. et sin. This entire cavity is lined by the dura mater, which covers it from above in the form of diaphragma sellae turcicae. Through its opening passes the infundibulum, which connects the pituitary gland in its posterior lobe with the brain. The cavity infundibuli, which is a recess of the bottom of the third ventricle, in some animal species (e.g., in dogs) passes as recessus infundibuli into the cavity of the posterior pituitary lobe (in humans this lobe has no cavity).


1992 ◽  
Vol 76 (6) ◽  
pp. 944-947 ◽  
Author(s):  
Takashi Nagaya ◽  
Akio Kuwayama ◽  
Hisao Seo ◽  
Nobuhiro Tsukamoto ◽  
Nobuo Matsui ◽  
...  

✓ It has been hypothesized by Lamberts and coworkers in their analysis of 15 cases that adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas may be derived from either the anterior lobe or the intermediate lobe. The intermediate lobe type of Cushing's disease is thought to be controlled through a hypothalamic pathway and is characterized by hyperprolactinemia, suppressibility of Cortisol with bromocriptine, and lower sensitivity to dexamethasone. The authors investigated the validity of this hypothesis in 125 cases of ACTH-secreting pituitary microadenomas by analyzing the endocrine findings, the locations of the microadenomas, and α-melanocyte stimulating hormone (α-MSH) immunoreactivity in the adenoma cells. No significant differences in the basal hormone levels, Cortisol suppressibility with bromocriptine, sensitivity to dexamethasone, and recurrence rate were observed between patients with the microadenoma adjacent to the posterior lobe (considered typical of the intermediate lobe-derived tumor) or those with the microadenoma located in the anterior lobe. The locations of the microadenoma were not correlated with α-MSH immunoreactivity in the adenoma cells. No significant differences in endocrine findings were noticed between adenomas positive or negative for α-MSH. Thus, Cushing's disease cannot be simply divided into either the anterior lobe type or the intermediate lobe type by endocrinological evaluation as described by Lamberts, et al.


1973 ◽  
Vol 59 (1) ◽  
pp. 17-29 ◽  
Author(s):  
W. B. WATKINS

SUMMARY Three neurophysins have been isolated from acetone-dried sheep posterior lobe powder and have been named neurophysins I, II and III. Neurophysins I, II and III account for approximately 15, 15 and 70%, respectively of the total neurohypophysial hormone-binding proteins present in the sheep posterior pituitary lobe. All the neurophysins bind oxytocin and [8-arginine]-vasopressin. Neurophysins I and II each were found to contain one molecule of histidine/molecule of protein but to lack methionine, whereas neurophysin III contained no histidine but had one molecule of methionine/molecule of protein. The molecular weights of sheep neurophysins I, II and III were 11348, 9803 and 10377, respectively, as determined by amino acid analysis. An approximate value of 10000 was estimated for the apparent molecular weight of the neurophysins by gel exclusion chromatography on Sephadex G-75. Solid amorphous complexes were formed between the neurophysins and oxytocin as well as with [8-arginine]-vasopressin. In each case one molecule of neurophysin complexed with one molecule of hormone. The stoichiometry of the sheep neurophysins relative to the neurohypophysial hormones is discussed.


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